The invention relates to a dock device comprising a bottom for supporting a ship or the like and longitudinal walls rising up from the bottom, a carriage adapted to travel along a longitudinal wall by driving means, an arm pivotally and deflectably connected with said carriage, swinging and deflecting means for moving said arm with respect to the carriage, a head carrying a processing member and being rotatably and tiltably connected with the free end of the arm and tilting and rotating means for moving said head with respect to the arm.
In order to ensure a satisfactory operation of the processing member concerned it has, in general, to be held at a fixed, constant distance from the wall to be treated. From French Patent Application No. 2,441,578 a dock device of the kind set forth is known, in which said constant distance is maintained by means of swivelling wheels mounted on the head. It has been found that such swivelling wheels do not satisfactorily guide the head. As a result the treatment of the wall by means of processing member is less satisfying.